Hi Folks,

In going through my '85 XJ6 engine I think I have found a vacuum leak in the Extra / Auxiliary Air Valve. I tested it by disconnecting the hoses at each end, plugging one end and applying vacuum on the other end. It leaks down pretty quickly.

Before I pronounce it bad, I want to visually check the bottom hose and its connection to the valve. To do that I have to remove the valve from the coolant rail (because I can't even see the top end of the bottom hose from above OR below the engine).

Is there a gasket between this part and the coolant rail? Do I need to drain the coolant a bit before I unbolt the valve? Does the valve, or its attaching screws, even come into contact with coolant?

Thanks,

-mB

 

No gasket, no contact with coolant.

The screws are torx or allen-key....can't remember which....but they're a little tricky to undo because of the position.

Cheers
DD

 

Thanks a lot, Doug. I guess that's why I couldn't find a part number for it.

"they're a little tricky to undo because of the position."

Why am I not surprised?

-mB

 

Mike,

It's not too unusual for that lower hose to be dried and brittle. If you can get under the car, you can reach up and check it without removing the AAV.... You'll find there isn't a lot of free play in the AAV hose, so if you remove it, there's a chance the back side of the hose will break off clean with the fitting on the AAV....
Bolts are a small torx..

Cheers
David
Everyday XJ

 

I got the valve off with no problem (finally, something that was no problem). I had already detached the hose from the manifold, so it just came out with the valve. The lower hose was uncracked but loose. But when I tested the valve itself I found it does leak vacuum. It seems like it is leaking around where the electric connector attaches. Given the price of these things I may try to "caulk" around the connector with some JB weld and see if that works.

-mB